Second - class current in τ → πην analysis and measurement of τ → hh ′ h ′ ′ ν from Belle ∼ Electroweak physics from Belle ∼

Based on a 670 fb −1 data sample accumulated at the Belle detector, we have looked for a second-class current decays τ → πην and τ → πη (958)ν. First possible indications for the τ → πην decay are attained with a 2.4 significance corresponding to the branching fraction B(τ − → π − ην τ) = (4.4 ± 1.6 ± 0.8) × 10 −5 or B < 7.3 × 10 −5 at 90% confidence level. Also, the upper limit on B(τ − → π − η (958)ν τ) is set as 4.6 × 10 −6 at the 90% confidence level. We have also measured the branching fractions for τ decay into three charged pseudoscalars, and examined their invariant mass distributions.